Actually, the norm in the past many decades in the US was a very liberal press, where people could publish on subversive topics of all kinds. The "left" supported broad first amendment rights on practically any topic. Now, they actively seek to censor and silence those who question or criticize a narrative, and with regard to covid those who question government policy. It's a bizarre and disorienting shift.

It's really the present day that suggest that substack won't be able to stick to their guns out of fear of organized opposition from "mobs". If they're able to maintain dependence only on subscribers, it's possible they can survive (and hopefully thrive) -- until somebody gets greedy.